Automatic ink supply for signal recorders



Sept. 10, 1940. R, D, H T HENS 2,214,636

AUTOMATIC INK SUPPLY FOR SIGNAL RECORDERS Filed Dec. 50, 1938 lNVENT WY/"0ND .D. UT'CHE/VS BY 7% ATTORNEY Patented Sept. 10, 1940 PATENT OFFICE aurom'rrc INK SUPPLY Foa SIGNAL anooansas Raymond D. Hutchens, Chicago, Ill., assignor to Radio Corporation of America, a corporation of Delaware Application December 30, 1938, Serial No. 248,478

3 Claims. (CL 178-96) This invention relates to ink reservoirs for telegraph recorders and similar devices.

It has longbeen the practice to record signals such as the Morse and similar codes on moving tapes .in land-line, cable and radio telegraphy. The hollow stylus or pen used to mark the dots and dashes or equivalent on such tapes has one end moving in a slot in a head supplied with ink -by a flexible tube connected to an ink pot and the other end moving against or adjacent the tape. The-ink flows into the slot through the tube by the combined force of gravity and capillarity and the inkpot is supported so that it can be raised and lowered in respect to the ink slot to permit the ink to flow into the slot.

The slot is narrow enough so that the capillary attraction prevents the ink from flowing out of the slot so long as the hydrostatic pressure from the inkpot stayswithin narrow working limits.

Frequent adjustments of the inkpot is required in practice and i1 great care is not used in ma ing these adjustments the pressure is likely to increase suiiiciently to cause the ink to overflow through the pen slot; The inkpot is either open at the top or is covered by a loose fltting cap so that air can flow into the assembly at the top. The rate of evaporation is accordingly high. This is not only wastes ink but also renders the remainder murky and less fluid whereby caking frequently results. I

It is an object of my invention to produce an ink supply system for recorders that reduces evaporation to a minimum, requires no hand adjustment of ink level and prevents overflow and .caking.

Another object of the invention is to maintain the level of the ink in the feed chamber within suitable narrow limits that prevents overflow and maintains an adequate supply of ink for an extended period.

Another object is to employ an automatic feed chamber that maintains the ink level within nar-' Fig. 2 is a plan view of the supply chamber and reservoir shown in Fig. 1.

Fig. 3 is amodiflcation. Referring to Fig. l, a hollow stylus or pen I has one end movably positioned in the ink slot 2 and the other sufficiently close to moving tape 3 to bring the ink in the pen against the tape for recording signals such as shown at l. The pen is moved up and downin Fig. 1 by any well known mechanisim not shown. The tape is moved to the right in Fig. 1 by well known ratchet or other feed mechaniism that also is not illustrated. These parts specifically are not parts of my invention and need not be further described since they are well known.

'I'he narrc'y ink slot 2 is formed in a head i and communicates with a supply reservoir 6 by a suitable tube 1.

Reservoir 6v is hermetically sealed at the top and is attached to a small inkpot '8 having a hinged top 9 that may be lifted by any suitable arrangement such as a projecting tab ID. This lid makes a fairly tight lit with. the inkpotas sufllcient air leaks in around the hinge II to permit the ink level to change as later described.

The interior of the inkpot communicates with the interior of the supply chamber only through .in the pen for recording. The ink in chamber 6 will be held at level I3 by barometric pressure and the level in head 5 is maintained by adhesion between the ink and the walls of slot 2 in opposition to gravity. The height of the ink in the slot therefore depends to some extent upon the hydrostatichead, that is, on the height of the ink level it in potl. Ink is drawn by capillary attraction through pen I and deposited on the tape 3 in recording signals. whensufllcient ink has been used by the pen the level H of the ink chamber l3. This permits a corresponding'volume of ink from chamber 8' to flow into inkpot 8, lowering the level l3 and raising the level It above slot II. This cycle will be repeated as long as the pen uses ink, until the ink in chamber 8 is depleted down to the opening in the tube 1. However, before this much ink is used the chamber 3 would be filled by the operator. The fllling can be accomplished by tilting the assembly so that the inkpot 8 and slot I2 are on top and then flowing ink through a small tube inserted through inkpot I and slot I 2. I I

In Fig. 81 have shown the pen slot} communicating directly with the interior of inkpot I.

in pot 8 will fall to slot i2 whereupon an air 40 bubble will pass through the ink slot I2 into Similar parts in Figs. 1 and 3 have been given similar reference characters and the operation of this modification will be readily understood. It is practically the same as that of Fig. 1, the only diiierence being that the ink is fed from inkpot 8 directly to the pen slot 2 and the ink for chamber 6 refills the inkpot to its originallevel.

Various other modifications may be devised without departing from the spirit of the invention.

Having described my invention, what I claim 1. In an ink supply for pen-type recorders, a supply head having a narrow ink slot a recording stylus having one end adapted to move in said slot for receiving its ink supply, an ink pot communicating with said slot and means to automatically replenish the ink in said pot when it lowers a predetermined amount.

2. In an ink supply for pen-type recorders, a

' supply head having a narrow ink slot, a recording stylus having one end adapted to move in said slot for receiving its ink supply an ink pot open at the top to atmospheric pressure, an ink supply chamber closed at the top to atmospheric pressure, said slot, pot and chamber being interconnected, the connection between the pot and chamber being a restricted opening near the bottom of each.

3. In an ink supply ior pen-type'recorders, an ink chamber closed at the top to atmospheric pressure, an inkpot open to atmospheric pressure at the top and connected to the chamber by a relatively small opening at the bottom, said chamber and pot being closed at the bottom except for said openings, 2. supply head having a narrow slot connected to said inkpot through an opening near the bottom.

RAYMOND D. HUTCHENS. 

